package date_202405

//36. 有效的数独
//中等
//相关标签
//相关企业
//请你判断一个 9 x 9 的数独是否有效。只需要 根据以下规则 ，验证已经填入的数字是否有效即可。
//
//数字 1-9 在每一行只能出现一次。
//数字 1-9 在每一列只能出现一次。
//数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。（请参考示例图）
//
//
//注意：
//
//一个有效的数独（部分已被填充）不一定是可解的。
//只需要根据以上规则，验证已经填入的数字是否有效即可。
//空白格用 '.' 表示。
//
//
//示例 1：
//
//
//输入：board =
//[["5","3",".",".","7",".",".",".","."]
//,["6",".",".","1","9","5",".",".","."]
//,[".","9","8",".",".",".",".","6","."]
//,["8",".",".",".","6",".",".",".","3"]
//,["4",".",".","8",".","3",".",".","1"]
//,["7",".",".",".","2",".",".",".","6"]
//,[".","6",".",".",".",".","2","8","."]
//,[".",".",".","4","1","9",".",".","5"]
//,[".",".",".",".","8",".",".","7","9"]]
//输出：true
//示例 2：
//
//输入：board =
//[["8","3",".",".","7",".",".",".","."]
//,["6",".",".","1","9","5",".",".","."]
//,[".","9","8",".",".",".",".","6","."]
//,["8",".",".",".","6",".",".",".","3"]
//,["4",".",".","8",".","3",".",".","1"]
//,["7",".",".",".","2",".",".",".","6"]
//,[".","6",".",".",".",".","2","8","."]
//,[".",".",".","4","1","9",".",".","5"]
//,[".",".",".",".","8",".",".","7","9"]]
//输出：false
//解释：除了第一行的第一个数字从 5 改为 8 以外，空格内其他数字均与 示例1 相同。 但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无效的。
//
//
//提示：
//
//board.length == 9
//board[i].length == 9
//board[i][j] 是一位数字（1-9）或者 '.'

func isValidSudoku(board [][]byte) bool {
	for i := 0; i < 9; i++ {
		rowVals := make(map[byte]struct{})
		colVals := make(map[byte]struct{})
		matVals := make(map[byte]struct{})
		for j := 0; j < 9; j++ {
			if board[i][j] != '.' {
				_, exist := rowVals[board[i][j]]
				if exist {
					return false
				}
				rowVals[board[i][j]] = struct{}{}
			}

			if board[j][i] != '.' {
				_, exist := colVals[board[j][i]]
				if exist {
					return false
				}
				colVals[board[j][i]] = struct{}{}
			}

			matBeginX := int(i%3) * 3
			matBeginY := int(i/3) * 3
			matI := j%3 + matBeginX
			matJ := j/3 + matBeginY

			if board[matI][matJ] != '.' {
				_, exist := matVals[board[matI][matJ]]
				if exist {
					return false
				}
				matVals[board[matI][matJ]] = struct{}{}
			}
		}
	}
	return true
}
